To shim or not to shim

[Guest]

Hey guys, I have just finished with filling in Steve's spreadsheet, Thanks again Steve!, and all my clearances fall well within tolerances.

The closest to minimum I have is at .04mm and all the rest with the exception of one valve are at .05mm.

In the process of recording my information and getting current shim sizes I found two valves to have shims with either no markings or they are worn off.
My questions are these:
Would you all worry about getting those shim sizes?

Would you wait for the next check and then record the missing shim sizes?

Would you go ahead and bring all clearances to .09 or .10mm?

[Nessism]

It's in spec so I'd leave it alone. It's nice to know what shims are in there so you can have the proper shims on hand for your next check, but if you didn't measure/record them and the valve cover is already on, I'd wait and deal with it later.

[cowboyup3371]

Agreed with Ed. However, get yourself a caliper, either digital or analog, and have it handy for next time

[Steve]

I have just finished with filling in Steve's spreadsheet, Thanks again Steve!

You're welcome.

In the process of recording my information and getting current shim sizes I found two valves to have shims with either no markings or they are worn off.
My questions are these:
Would you all worry about getting those shim sizes?

As Nessism said, if it's all buttoned up, do it next time.

The nice thing about knowing what's in there is that you only have to do that inventory ONCE.
If the clearance is off, you know what you need, because you already know what's in there.

.

[Indysteve]

Thanks guys, I figured as much but I figured I needed to hear any negative to not doing the recording now as opposed to later.

Would you guys go ahead and shim them up to .10 or would you wait until the next check?

The reason I ask is that if I leave them this way I am worried I will not get a full season out of them before I need to check them again?????

Or am I just being the worry wart and should not expect them to wear so quickly?

[Steve]

They don't all need to be adjusted every time.

At least you did the important part, the measuring.

Recording values for the remaining shims can wait, you at least have the comfort of knowing that your clearances are good.

.

[bwringer]

I live in Indy and have a large collection of shims and the measuring tools to decipher unmarked shims.

Don't worry about it now -- you're in spec -- but in 4,000 miles at the next valve check, feel free to give me a holler.


To answer the original question, if I happen to have an "X" shim (these are the slightly "fatter" in-between shims sometimes used by the factory) or the next shim thinner that will open up a marginal .04mm clearance a bit, I will use it. If I don't, it's not usually worth a trip to CRC2 for a new shim -- just something to note for next time. You'll be fine until the next valve check.

[Indysteve]

Thanks for the offer Brian I will take you up on it in the future

Funny thing, I went to Harbor Freight and bought a digital micrometer today.
I looked all over and could not find my dial calipers the other day when I ran across this problem...... Oh well I will put them to good use!!